Mechanical and physical properties of synthetic sustainable geopolymer binders manufactured using rockwool, granulated slag, and silica fume

Abstract

The substantial target of this work is to manufacture sustainable geopolymers by recycling low cost industrial wastes (granulated slag, GS; rockwool, RW; and silica fume, SF). To reveal the mineral and chemical compositions of these industrial solid wastes, they were investigated using X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). The granulated slag, rockwool and silica fume were blended with the convenient quantity of alkaline reactor to formulate a hydrated pattern of geopolymers. The phase configuration, physico-mechanical effects [compressive strength (CS), porosity and bulk density] and the microstructural form of the geopolymers were studied via the X-ray diffraction, hydraulic mechanical testing device, helium pycnometer, and Field emission Scanning electron microscope (FE-SEM), respectively. The results declared that the partial substitution of RW by various ratios of SF in presence of GS affect successfully on the physico-mechanical properties of hardened geopolymers. Implication of 2 % SF boosts the physico-mechanical features of the 50GS-48RW hardened geopolymers at all curing ages especially at the age of 28 days. Therefore, the geopolymer 50GS-48RW-2SF displayed the best physico-mechanical characteristics especially the CS at 28-days (39.12 MPa) owing to the formation of diverse hydration products like CSHS, CAHS and NASHs. These results were confirmed via FE-SEM/EDX images that exhibited compact and dense microstructure rod-like crystals of CSHs and three dimensional framework structures of NASHs.